THE NASAL BONES. 133 
which passes obliquely upwards and outwards through the orbital process and 
appears in the temporal fossa, to the inner side of the frontal process (foramen 
zygomatico-temporale). The former transmits the ramus subcutaneus male; the 
latter the temporal branch of the orbital nerve. 
Below the orbital process there is a rough triangular area, bounded externally 
by the maxillary border. This articulates with the malar process of the superior 
maxilla and occasionally forms the outer wall of the antrum. 
Connexions.—The malar bone articulates with the frontal, sphenoid, superior maxilla, and 
temporal bones. 
Architecture.—In structure the bone is compact, with little cancellous tissue. Together 
with the zygomatic process of the temporal bone it forms the buttress which supports the superior 
maxilla and the outer orbital wall externally. Additional strength is imparted to the bone by 
the angular mode of union of its orbital and facial parts. 
Variations.—Cases of division of the malar bone by a horizontal suture have been recorded, 
as well as instances of its separation into two parts by a vertical suture. Owing to the supposed 
more frequent occurrence of this divided condition in Asiatics the malar has been named the os 
Japonicum. Barclay Smith (“ Proc. Anat. Soc.” Journ. Anat. and Physiol. April 1898, p. 40) 
describes a case in which the malar bone was divided into two parts, an upper and lower, by a 
backward extension of the maxilla, which articulated with the zygomatic process of the temporal, 
thus forming a temporo-maxillary arch. Varieties of a like kind have also been described by 
Gruber and others. Cases have been noted where, owing to deficiency in the development of the 
malar, the continuity of the zygomatic arch has been incomplete. 
Ossification.—The malar ossifies in membrane most probably from three centres, 
disposed as follows: one in the posterior part of the bone, the other two in connexion 
with the orbital process and orbital margin. Appearing as early as the eighth week, these 
centres are confluent by the beginning of the fifth month of foetal life. 
THE NASAL BONES. 
The nasal bones (ossa nasalia), two in number, lie in the interval between the 
frontal processes of the superior maxilla, there forming the root or bridge of the 
nose. Kach bone is of elongated quad- 
rangular form, having two surfaces— 
an inner and outer—and four borders. 
The external surface, somewhat con- 
stricted about its middle, is convex 
from side to side, and slightly concavo- 
convex from above downwards. Near 
its centre there is usually the opening 
of a nutrient canal. 
The internal surface is not so ex- 
tensive as the external, as the superior 
and anterior articular borders encroach 
somewhat upon it above. Concave 
from side to side and also from above 
downwards it is covered, in the recent 
condition, by the mucous membrane of the nose. Running downwards along this 
surface is a narrow groove (sulcus ethmoidalis), which transmits the internal nasal 
nerve. The anterior or internal border, narrow below, is thick above, and, i con- 
junction with its fellow at the opposite side, with which it articulates, forms a 
median crest posteriorly, which is united to the nasal spine of the frontal, the 
vertical plate of the ethmoid, and the septal cartilage of the nose, in that order from 
above downwards. The posterior or external border, usually the longest, is serrated 
and bevelled to fit on to the anterior edge of the frontal process of the superior 
maxilla. The superior border forms a wide toothed surface, which articulates with 
the inner part of the nasal notch of the frontal bone anteriorly ; whilst, behind, 
it rests in contact with the root of the nasal process of the same bone. The 
inferior border is thin and sharp, and is connected below with the lateral cartilage 
of the nose, and is usually deeply notched near its mesial extremity. 
/ Nasal crest 
Groove for 
nasal nerve 
Vascular foramen 
Maxillary 
border 
B 
Fira. 104.—Ricut Nasat Bone. A, Outer side ; 
B, Inner side. 
Connexions.—The nasal bone articulates with its fellow of the opposite side, with the 
frontal above, behind with the mesial plate of the ethmoid and with the frontal process of the 
superior maxilla. It is also united to the septal and upper lateral cartilages of the nose. 
7 
